The NBER Program Project on the Economics of Aging is a coordinated set of research projects on the health and economic circumstances of individuals as they age and on the implications of population aging. Funded initially in 1986, its six major themes are: work and retirement behavior, financial circumstances, health and health care, relationships between socioeconomic circumstances and health, population aging around the world, and behavioral economics. There are eight projects proposed for the next five year phase of the program. Project 1 extends ongoing work on financial status, focusing on the drawdown of assets after retirement and their relationship to family transitions and health shocks. Project 2 analyzes the economic, psychological, environmental, genetic, and biological factors that together influence economic decision-making, including analysis of experimental interventions that induce welfare-enhancing behavior change in health and saving. Project 3 dissects the multiple dimensions of health among the U.S. elderly population, the pathways through which health and functional ability decline, and how population health and disability are changing over time. Project 4 extends ongoing work on social security systems and retirement around the world, but with a new emphasis on how disability programs and health interact in influencing labor market behavior at older ages. Project 5 extends ongoing work on aging, health, and well-being with an expanded focus on the links between socioeconomic factors and health in early and later life, and on measuring well-being. Project 6 extends ongoing work on life conditions in a poor region of rural India, including analytical work on two completed experimental health interventions and the implementation of a new intervention on the impact of increased pension allowances. Project 7 studies the relationship between economic circumstances and health by analyzing in detail how recent declines in financial and housing markets are affecting health. Project 8 analyzes the characteristics and root causes of racial disparities in health and health care.